Not Applicable.
1. Field of the Invention
The present invention relates to a golf club head. More specifically, the present invention relates to a golf club head composed of a composite material.
2. Description of the Related Art
In recent years, substantial attention has been directed toward the development of golf club heads having desired weight characteristics and, in particular, toward the development of golf club heads having a desired center of gravity location. For example, a designer may want to locate the center of gravity of a golf club head in a predetermined or preferred position relative to the face or xe2x80x9csweet spotxe2x80x9d of the golf club head so as to make the golf club head more forgiving upon the occurrence of off-center hits.
Because conventional golf club heads are typically made from metal alloys or other materials having a substantially homogeneous density, the weight characteristics of such golf club heads are typically defined by their overall shape. Thus, to alter the location of the center of gravity of a golf club head, it is often necessary to redesign the shape or configuration of the golf club head. However, this may adversely impact other desired characteristics of the golf club head.
The design process may be further complicated where golf club heads are manufactured using composite materials. Because composite materials are typically less dense than metal and other conventional materials, composite golf club heads generally require additional weighting to achieve desired swing weights for finished golf clubs.
The Rules of Golf, established and interpreted by the United States Golf Association (xe2x80x9cUSGAxe2x80x9d) and The Royal and Ancient Golf Club of Saint Andrews, set forth certain requirements for a golf club head. The requirements for a golf club head are found in Rule 4 and Appendix II. A complete description of the Rules of Golf are available on the USGA web page at www.usga.org. Although the Rules of Golf do not expressly state specific parameters for a golf club, Rule 4-1d states that the club head shall be generally plain in shape, and all parts shall be rigid, structural in nature and functional.
Many solutions have been proposed to adjust and/or increase the weight of composite golf club heads. For example, a weighting agent or material is often introduced into a cavity within a golf club head subsequent to manufacture. In the case of wood type golf club heads, the cavity may be enclosed by the face, sides, sole and crown of the golf club head. However, it is not uncommon for cavities also to be formed, for example, in the sole, heel or toe regions of iron or putter type golf club heads. Because of limited access to the cavities, however, such weighting materials may not be placed as precisely as desired and may not provide the ability to adjust the weight of the golf club heads, or the location of the center of gravity of the golf club heads, very precisely. Furthermore, such materials may dry and separate from the walls of the golf club heads during use, adversely affecting the weight of the golf club heads and possibly creating a distracting sound or feel when the golf clubs are swung.
Alternatively, a composite golf club head may be provided with a metal sole plate or, in the case of wood type golf club heads, a solid or foam core. However, the use of metal sole plates may add undesirable steps in the process of making the golf club heads, and the use of solid or foam core materials has been shown generally to be ineffective for adjusting the location of the center of gravity and moments of inertia of golf club heads. The reason for this is that solid or foam core materials generally have a uniform density, making it difficult to adjust the location of the center of gravity or moments of inertia of the golf club head without simultaneously altering the shape or configuration of the golf club head. Additionally, such materials may result in voids within the golf club head.
For a golf club head including composite material, higher density layers of composite fiber may be provided in the wall of the golf club head to increase its weight. However, such changes in the layers of composite material may affect the structural characteristics of the golf club head.
In view of the foregoing, there appears to be a substantial need for improved methods of manufacturing composite golf club heads and, in particular, for methods that allow for more effective adjustment of the weight characteristics of golf club heads without substantially affecting the structural characteristics of the golf club heads.
There also appears to be a need for improved composite golf club heads manufactured in accordance with such methods.
One aspect of the present invention is a composite golf club head having a weight strip in a ribbon section of the club head. The golf club head has a body having a hollow interior and is composed of a composite material. The body has a face, a sole, a crown, a ribbon juxtaposed by the sole and the crown, a heel end and a toe end. The golf club head also has a weight strip composed of a material having a density greater than the composite material. The weight strip is disposed on the ribbon.
Another aspect of the present invention is a composite golf club head having multiple weight strips in a ribbon section of the club head. The golf club head has a body having a hollow interior and composed of a composite material. The body has a face, a sole, a crown, a ribbon juxtaposed by the sole and the crown, a heel end and a toe end. The golf club head also has a plurality of weight strips. Each of the plurality of weight strips is composed of a material having a density greater than the composite material. Each of the plurality of weight strips is disposed on the ribbon. Each of the weight strips is shaped to occupy a predetermined space within the ribbon. The number of weight strips may range from two to fifty, preferably two to ten, and most preferably three.
Yet another aspect of the present invention is a method for producing a composite golf club head having a weight strip embedded in its ribbon. The method includes placing layers of plies of pre-preg sheets in a mold. The mold has the shape of a golf club head having a face, a sole, a crown, a ribbon juxtaposed by the sole and the crown, a heel end and a toe end. The method also includes placing a weight strip in the ribbon area of the mold. The method also includes curing the layers of plies pre-preg sheets and weight strip to create a golf club head composed of a composite material with a weight strip therein.
The golf club head of the present invention is composed of a plurality of plies of pre-preg, has a tungsten weight strip, has a volume of greater than 320 cubic centimeters, and has a weight ranging from 188 to 195 grams.
Having briefly described the present invention, the above and further objects, features and advantages thereof will be recognized by those skilled in the pertinent art from the following detailed description of the invention when taken in conjunction with the accompanying drawings.